The present embodiments relate to identification of orientation. In particular, orientation of flow or structure is determined for medical diagnostic ultrasound imaging.
Medical diagnostic ultrasound imaging may be used to show flow with respect to tissue, such as flow mode image overlaid with a B-mode image. B-mode data determines whether a given location is associated with tissue or with flow. A B-mode value above a threshold indicates a location associated with tissue. Color bleed from flow data over vessel walls represented by B-mode data occurs since B-mode amplitude alone may not be an adequate identifier of vessel walls. At low velocity scales, significant flash may occur in flow imaging, since B-mode amplitude may not sufficiently identify valid tissue and anatomical structures. Further thresholding may be provided, such as removing flow information below a velocity and/or energy threshold. Removal may create holes in the flow representation.
The B-mode and flow mode data are acquired along a plurality of scan lines. For flow mode, velocity information represents motion along the scan lines. Depending on the location of the structure scanned, the flow may not be only along the scan lines. The velocity information may be inaccurate since flow perpendicular to the scan line may not be detected.